Pivotable handle actuated fluid valves have been in existence for some time in which a slideable valve plunger is spring biased so as to project against a pivotable handle carried by the valve body to maintain the valve closed and to prevent fluid connection between a pressure fluid supplied to an inlet passage which is parallel to but offset from an outlet passage within the valve body. The axially displaceable plunger functions to selectively fluid communicate the inlet passage to the outlet passage of the valve structure. Such valve structures have been typically formed of metal. U.S. Pat. No. 1,184,365 to Luhrs shows such a valve structure which incorporates a transverse or right angle communication passage between the offset inlet and outlet passages as comprised of a bore and counterbore which bear a plunger having a land or enlarged peripheral portion within the counterbore which functions as the movable valve member and which seats against a radial shoulder leading to the bore, within which is slidably mounted the smaller diameter portion of the plunger. Further, the Luhrs patent shows a coil spring, having one end which which fits within a central recess within the interior face of a cap which is threaded to the body at the end of the counterbore and the other end abutting the plunger. The compressed coil spring functions to bias the slidable plunger to valve closed position. Further, the end of the smaller diameter portion of the plunger projects from the bore to contact a spring biased actuator which is pivoted to the valve body and which may be grasped and pivoted to force the plunger, against the bias of the spring, to shift to an axially displaced position where the large diameter land unseats from the valve seat and permits fluid flow from the inlet passage to the outlet passage.
In addition to the formation of air and liquid valves of components of cast or machined metal, attempts have been made to form valve structures where at least the valve body is formed of a molded plastic as evidenced by U.S. Pat. No. 3,539,151 to Reid et al. While the incorporation of plastic molded components has to some extent reduced the number of components and has resulted in a somewhat simplified valve structure, there are no valve structures known to applicants in which all of the components except the biasing spring and seal elements are formed of molded plastic, and wherein the complexity and overall size of the valve have been substantially reduced, in comparison with metal on/off valve assemblies.
Within the last decade, there has developed a hot water vacuum extraction cleaning machine which has found appreciable consumer acceptance particularly for the home or household cleaning of wall-to-wall rugs or the like. Such a hot water vacuum extraction machine, as exemplified by the products of the assignee of this application, comprises a casing structure bearing a tank where water may be heated for supply to a spray nozzle mounted on a vacuum pick up head, which in turn is fixed to the end of a vacuum return wand for the steam cleaner. The water supplied by the hot water supply tank is sprayed onto the surface such as the rug to be cleaned adjacent to the vacuum pick up head. The vacuum return wand normally constitutes a light weight plastic or aluminum tube held by the operator and the vacuum head at the end of the tube is moved over the surface to be cleaned. By vacuum pressure application to a dump tank connected to the wand, the liquid after cleaning of the rug surface adjacent to the mouth of the vacuum head is picked up by the head and returned through the head and wand to the dump tank where the water is separated from the air employed in the vacuum pick up. Upon accumulation of a sufficient volume of dirty water in the dump tank, the dump tank is removed from the unit and the accumulated water is dumped.
In order to control the spray of hot water through the nozzle, there is normally provided within the hot water line or hose leading from the hot water tank to the spray nozzle, a spring biased on/off valve including a handle type valve operator or actuator. The actuator handle is grasped by the operator and is pivoted so as to depress a valve plunger and permit the fluid connection between the inlet and outlet passages of the valve. Additionally, the valve is clamped to the vacuum return wand and serves as the means for physically mounting a portion of the water supply hose to the wand at one end, the opposite end of the water supply line bearing the spray nozzle being mounted to one face of the vacuum pick up head.
U.S. Pat. No. 4,009,728 issuing Mar. 1, 1977 and assigned to the common assignee, is exemplary of a water valve assembly to which the present invention constitutes and improvement. In that patent the water valve assembly is mounted to the vacuum return wand of the hot water vacuum extraction machine or steam cleaner and includes a water valve of the type having an outwardly biased actuating member which prevents the passage of water in its normal position and permits the passage of water when pressed inwardly. The assembly comprises two mating mounting brackets shaped to receive portions of the periphery of the vacuum return wand and the water valve with a shaft passing through the mounting bracket between the vacuum return wand and the water valve and a lever arm mounted on the shaft in two mounting brackets and means for urging the two mounting brackets together so as to firmly grasp the vacuum return wand and the water valve therebetween. Such water valve assembly includes a number of separate components forming the mounting bracket and which are completely separate from the valve bearing the spring biased plunger or valve actuating member which normally prevents flow absent depression of the plunger between an axially aligned inlet and outlet passages within the valve body.
It is, therefore, a primary object of the present invention to provide an improved, fast acting, simplified on/off valve which is preferably formed of molded plastic components and which is preferably non-repairable, and wherein the valve is characterized by a double seal when in valve closed position with a highly effective resilient O-ring seal type valve seat contacting a conical valve plunger land.